STB5600TR

Note that the mixer output is low impedance,(70 Ohms),and the IF input is high impedance(15kOhms),

so considerablevoltage gain is achievedin the impedance matching filter.

The filter also sets the bandwidth of the receiver, using the load impedance with the L/C ratio to set the

filter Q. If desired, an external resistor may be added in parallel to reduce the Q. Note that the

bandwidth must be much wider than the 2MHz needed to pass the power of the GPS signal... it must

maintain linear phase across the 2MHz, even at the extremesof component tolerance.

Fig. 4 Matching Networkwith four elements

Fig. 5 IF Filter

A.3 Reference Oscillator

The recommended dual output oscillator shown in figure 6 generates both the 81.84MHz signal that is

Fig. 6 ReferenceOscillator

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